The present invention is directed to a fastening member assembly, which is driven into a hard receiving material by an explosive powder charge operated setting tool. The fastening member assembly includes a shank with a tip at its leading end and a load engagement member at its trailing end with the load engagement member forming a shoulder projecting radially outwardly from the shank.
Fastening members of the above-described type are driven into hard receiving materials, such as concrete, masonry, rock, steel and the like. The fastening members are driven into the hard receiving material by explosive powder charge operated setting tools. A preferred use for such attachment members is for securing or connecting support members to the receiving material. Such support members can be in the form of holding or retaining parts serving to fix cable, tubes, insulation panels, extension members and the like. The fastening of such retaining parts occurs in such a way that after the driving process has been terminated, a shoulder of a load engagement means abuts or is supported at the retaining part and secures it against the receiving material.
The load engagement means for the fastening members can be shaped as a head which projects transversely from the diameter of the shank. Instead of a head, the load engagement means can be a threaded part also projecting beyond the diameter of the shank. In addition to forming a shoulder, the threaded part also serves for receiving nuts or the like.
Connecting elements, in the form of a retaining part of the type mentioned above, are mostly formed of plastics material, on the one hand for reasons of economy and on the other hand for reasons of insulation. The use of plastics material for the retaining part creates certain problems with the type of fastening member assembly described here when explosive powder charge operated setting tools are used. It must be assured that the retaining parts are held or stressed sufficiently against the receiving material. This assumes a defined setting depth of the fastening member so that on one hand the danger of insufficient stressing is avoided or on the other hand the danger of destruction of the retaining part is excluded.
When securing fastening members with the use of explosive powder charge operated setting tools, it is difficult to determine in advance the setting depth of the fastening members. Such uncertainty arises in part due to the inhomogeneity of the receiving material and in part because of the variation in the energy output of the propelling charge being used. The danger of destruction of the retaining parts is considerable in view of these problems.